A cave automatic virtual environment (CAVE) projection system is a large virtual reality (VR) system, with high degree of immersion and interactivity. The CAVE projection system can fuse vision, touch, sound and other senses, and can track head movement along 6 degrees of freedom. The principles of the CAVE immersive virtual reality display system is relatively complex. The principles are based on computer graphics, and perfectly fuses the high-resolution three-dimensional projection display technology, multi-channel visual synchronization technology, three-dimensional computer graphics technology, audio technology, sensor technology and so on. The CAVE immersive virtual reality display system is therefore able to produce a completely immersive virtual environment surrounded by a three-dimensional projection images and can be used by multiple people. At present, real-time high-resolution multi-window content rendering of a complex scene is mainly applied to the CAVE system. The CAVE projection system is a large VR system with high degree of immersion and interactivity. The CAVE projection system is a highly immersive virtual demonstration environment composed of three or more (i.e. including three) hard rear-projection walls. An observer is surrounded by a virtual reality system having a plurality of images, and a virtual space is formed by a plurality of projection surfaces. The common CAVE system projection space is a standard cubic structure, and the four independent projection channels finally form a space continuous projection image.
At present, the interior of a common projector has only one set of optical engines which are equipped with one lens. Parameters of the optical machine (i.e the optical component) determine the size of the projected projection surface, and the projection surface projected with a large wide-angle is achieved by a fisheye lens. The cost of a large wide-angle projection is expensive and the output image from the fisheye lens results in serious deformation. Due to the limitations of the parameters of the optical machine, the common projector (including household and engineering), even with the fisheye lens, cannot achieve a wrap-around 360-degree image surrounding a user when projected by only a single projector. In order to project an image that fully surrounds the user (i.e. a surrounding image), multiple projectors are required to be arranged at different positions in the space, and the images projected by the multiple projectors are spliced through edge fusion technology. However, the defect in the prior art of using multiple projectors to achieve a projection in a surrounding manner or in a large scope is that a plurality of projectors need to be hung at different positions of the projection space, the equipment is not centralized, and it is difficult to manage and maintain the equipment. Since the projector is hung at a supporting frame/suspending frame, the relative position of the supporting frame (and therefore the relative position of the projector) changes slightly with time due to the weight of the projector. The relative position of the projector will change resulting in the image of the fused edge to be misplaced. The plurality of projectors are arranged separately, but need to work collaboratively with high precision, therefore once the above misplacement occurs, it is difficult to correct and causes a variety of problems when correcting the images.